Field Evaluation of Nitrogen Treatment by Conventional and Single-Pass Sand Filter Onsite Wastewater Systems in the North Carolina Piedmont

  • Charles P Humphrey
  • Jordan Jernigan
  • Guy Iverson
  • Brent Serozi
  • Michael O’Driscoll
  • Sushama Pradhan
  • Eban Bean


Excess nitrogen loading has contributed to the impairment of major watersheds across North Carolina. Onsite wastewater systems (OWS) are a potential source of nitrogen to water resources, but more research is needed to determine their actual contributions, especially in the Piedmont region of the state. The objective of this study was to determine the total dissolved nitrogen (TDN) treatment efficiency of four OWS in clayey soils of the North Carolina Piedmont. Two OWS were conventional style, and two were single-pass sand filters. The four volunteered sites with OWS were instrumented with piezometers (27 total) for groundwater collection and analyses. Piezometers were installed within 1.5 m of each OWS and downgradient from the conventional OWS. Septic tank effluent, groundwater from the piezometers, sand filter effluent, and adjacent surface waters were sampled bimonthly (five times) during 2015. Samples were analyzed for TDN, NO3-N, NH4+-N, chloride, dissolved organic carbon, and physical and chemical parameters on each sampling event. Groundwater samples collected 35 m downgradient from the two conventional OWSs had TDN concentrations and masses, on average, of 98 and 70 %, respectively, lower than septic tank effluent. Isotopic analysis of the natural abundance of δ15N and δ18O in NO3 in groundwater collected at the conventional OWS sites suggests that denitrification was a mass removal mechanism. The sand filter OWS reduced TDN concentrations by an average of 80 % and mass loading by 50 % prior to discharge to surface waters. Nitrogen management regulations in nutrient-sensitive watersheds should consider the contributions from OWS, especially direct discharge systems like sand filters. Improvements in the TDN treatment efficiency of direct discharge OWS would result in immediate surface water quality improvements.


Nitrogen loading Onsite wastewater Sand filters Soil treatment 


  1. Aravena, R., & Robertson, W. D. (1998). Use of multiple isotope tracers to evaluate denitrification in ground water: study of nitrate from a large-flux septic system plume. GROUND WATER, 36(6), 975–982.CrossRefGoogle Scholar
  2. Bradshaw, J. K., & Radcliffe, D. E. (2013). Nitrogen fate and transport in a conventional onsite wastewater treatment system installed in a clay soil: experimental results. Vadose Zone Journal, 12, 3. doi:10.2136/vzj2012.0149.Google Scholar
  3. Bunnel, J. F., Zampella, R. A., Morgan, M. D., & Gray, D. M. (1999). A comparison of nitrogen removal by subsurface pressure dosing and standard septic systems in sandy soils. Journal of Environmental Management, 56, 209–219.CrossRefGoogle Scholar
  4. Conley, D. J., Paerl, H. W., Howarth, R. W., Boesch, D. F., Seitzinger, S. P., Havens, K. E., Lancelot, C., & Likens, G. E. (2009). Controlling eutrophication: nitrogen and phosphorus. Science, 323, 1014–1015.CrossRefGoogle Scholar
  5. Cooper, J. A., Loomis, G. W., Kalen, D. V., & Amador, J. A. (2015). Evaluation of water quality functions of conventional and advanced soil-based onsite wastewater treatment systems. Journal of Environmental Quality, 44(3), 953–962.Google Scholar
  6. De, M., & Toor, G. P. (2015). Fate of effluent-borne nitrogen in the mounded drain field of an onsite wastewater treatment system. Vadose Zone Journal, 14, 12. doi:10.2136/vzj2015.07.0096.CrossRefGoogle Scholar
  7. Del Rosario, K. L., Humphrey, C. P., Mitra, S., & O’Driscoll, M. (2014). Nitrogen and carbon dynamics beneath on-site wastewater treatment systems in Pitt County, North Carolina. Journal of Water Science and Technology, 69(3), 663–671.CrossRefGoogle Scholar
  8. Domenico, P. A., & Schwartz, W. (1998). Physical and chemical hydrogeology (2nd ed., p. 115). New York: Wiley.Google Scholar
  9. Harden, S. H., Roeder, E., Hooks, M., & Chanton, J. P. (2008). Evaluation of onsite sewage treatment and disposal systems in shallow karst terrain. Water Research, 42, 2585–2597.CrossRefGoogle Scholar
  10. Havlin, J. L., Beaton, J. D., Tisdale, S. L., & Nelson, W. L. (1999). Soil fertility and fertilizers (6th ed., pp. 123–128). New Jersey: Prentice Hall.Google Scholar
  11. Holman, I. P., Whelan, M. J., Howden, N. J. K., Bellamy, P. H., Willby, N. J., Rivas-Casado, M., & McConvey, P. (2008). Phosphorus in groundwater—an overlooked contributor to eutrophication. Hydrological Processes, 22, 5121–5127.CrossRefGoogle Scholar
  12. Hoover, M. T., Daisy, T. A., Pfeiffer, M. A., Dudley, N., Mayer, R. B., & Buffington, B. (1996). North Carolina subsurface wastewater operators training school manual (section 4–2). Soil Science Department, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC and North Carolina Department of Environment. Raleigh, NC: Health, and Natural Resources.Google Scholar
  13. Humphrey, C. P., O’Driscoll, M. A., & Zarate, M. A. (2010). Controls on groundwater nitrogen contributions from on-site wastewater systems in Coastal North Carolina. Journal of Water Science and Technology, 62(6), 1448–1455.CrossRefGoogle Scholar
  14. Humphrey, C. P., O’Driscoll, M. A., Deal, N., Lindbo, D., Zarate-Bermudez, M. A., & Thieme, S. (2013). On-site wastewater system nitrogen contributions to groundwater in Coastal North Carolina. Journal of Environmental Health, 76(5), 16–22.Google Scholar
  15. Humphrey, C., O' Driscoll, M., & Harris, J. (2014). Spatial distribution of fecal indicator bacteria in groundwater beneath Two large onsite wastewater treatment systems. Water, 6(3), 602–619.Google Scholar
  16. Humphrey, C., Pradhan, S., Bean, E., O’Driscoll, M., & Iverson, G. (2015). Preliminary evaluation of a permeable reactive barrier for reducing groundwater nitrate transport from a large onsite wastewater system. American Journal of Environmental Sciences, Available at: Scholar
  17. Iverson, G., O’Driscoll, M.A., Humphrey Jr, C.P, Manda, A.K., and Anderson-Evans, E. (2015). Wastewater Nitrogen Contributions to Coastal Plain Watersheds, NC, USA. Water, Air and Soil Pollution. doi:10.1007/sll270-015-2574-4.
  18. Karathanasis, A. D., Mueller, T. G., Boone, B., & Thompson, Y. L. (2006). Nutrient removal from septic effluents as affected by soil thickness and texture. Journal of Water and Health, 4(2), 177–195.Google Scholar
  19. Kendall, C., & McDonnell, J. J. (1998). Isotope tracers in catchment hydrology (pp. 531–552). Amsterdam: Elsevier Science.Google Scholar
  20. Komar, S. C., & Anderson, H. W. (1993). Nitrogen isotopes as indicators of nitrate sources in Minnesota sand-plain aquifers. GROUND WATER, 31(2), 260–270.CrossRefGoogle Scholar
  21. Lapointe, B. E., Herren, L. W., Debortoli, D. D., & Vogel, M. A. (2015). Evidence of sewage-driven eutrophication and harmful algal blooms in Florida’s Indian River Lagoon. Harmful Algae, 43, 82–102.CrossRefGoogle Scholar
  22. Lowe, K. S., Rothe, N. K., Tomaras, J. M. B., DeJong, K., Tucholke, M. B., Drewes, J., McCray, J. E., & Munakata-Marr, J. (2007). Influent constituent characteristics of the modern waste stream from single sources: lit. Rev. Alexandria, VA, USA: Water Environment Research Foundation.Google Scholar
  23. Meeroff, D. E., Bloetscher, F., Bocca, T., & Morin, F. (2008). Evaluation of water quality impacts of on-site treatment and disposal systems on urban coastal waters. Water Air and Soil Pollution, 192, 11–24.CrossRefGoogle Scholar
  24. Nasr, F. A., & Mikhaeil, B. (2013). Treatment of domestic wastewater using conventional and baffled septic tanks. Environmental Technology, doi:10.1080/09593330.2013.767285.
  25. North Carolina Department of Agriculture and Consumer Services. (2016). Agronomic services-soil testing methodologies. Accessed May 2016 from web link: Scholar
  26. North Carolina Department of Environmental Quality. (2009). Lick creek watershed restoration plan (p. 19). accessed January, 2016.Google Scholar
  27. North Carolina Department of Health and Human Services. (2015). Onsite water protection branch: annual activity reports. Accessed December 2015 from web link: Scholar
  28. North Carolina Division of Water Resources. (2015). Nutrient strategies. Accessed December 2015.Google Scholar
  29. North Carolina Ecosystems Enhancement Program. (2006). Little Lick Creek watershed plan. Accessed December 2015 from web link: Scholar
  30. Oakley, S. M., Gold, A. J., & Oczkowski, A. J. (2010). Nitrogen control through decentralized wastewater treatment: process performance and alternative management strategies. Ecological Engineering, 36, 1520–1531.CrossRefGoogle Scholar
  31. O’Driscoll, M.A., Humphrey Jr, C.P., Deal, N.E., Lindbo, D.L., and Zarate-Bermudez, M.A. (2014). Meteorological influences on nitrogen dynamics of a coastal onsite wastewater treatment system. Journal of Environmental Quality. doi:10.2134/jeq2014.05.0227
  32. Osmond, D. L., Gilliam, J. W., & Evans, R. O. (2002). Riparian buffers and controlled drainage to reduce agricultural nonpoint source pollution, North Carolina Agricultural Research Service Technical Bulletin 318. Raleigh, NC: North Carolina State University.Google Scholar
  33. Pinay, G., Rufffinoni, C., Wondzell, S., & Gazelle, F. (1998). Change in groundwater nitrate concentration in a large river floodplain: denitrification, uptake, or mixing? Journal of the North American Benthological Society, 17(2), 179–189.CrossRefGoogle Scholar
  34. Postma, F. B., Gold, A. J., & Loomis, G. W. (1992). Nutrient and microbial movement from seasonally-used septic systems. Journal of Environmental Health, 55(2), 5–10.Google Scholar
  35. Potts, D. A., Gorres, J. H., Nicosia, E. L., & Amador, J. A. (2004). Effects of aeration on water quality from septic system leachfields. Journal of Environmental Quality, 33(5), 1828–1838.CrossRefGoogle Scholar
  36. Pradhan, S. S., Hoover, M. T., Austin, R. E., & Devine, H. A. (2007). Potential nitrogen contributions from on-site wastewater treatment systems to North Carolina’s river basins and sub-basins. North Carolina Agricultural Research Service. Raleigh, NC: North Carolina State University. Technical Bulletin 324.Google Scholar
  37. Pradhan, S., Hoover, M. T., Clark, G. H., Gumpertz, M., Cobb, C., & Strock, J. (2011). Impacts of biological additives, part 1: solids accumulation in septic tanks. Journal of Environmental Health, 74(5), 16–21.Google Scholar
  38. Reay, W. G. (2004). Septic tank impacts on ground water quality and nearshore sediment nutrient flux. Ground Water Oceans, 42(7), 1079–1089.CrossRefGoogle Scholar
  39. Richardson, J. L., & Vepraskus, M. J. (2001). Wetland soils: genesis, hydrology, landscapes, and classification (pp. 90–111).Google Scholar
  40. Robertson, W. D., Cherry, J. A., & Sudicky, E. A. (1991). Groundwater contamination from 2 small septic systems on sand aquifers. GROUND WATER, 29(1), 82–92.CrossRefGoogle Scholar
  41. Robertson, W. D., Ford, G. I., & Lombardo, P. S. (2005). Woodbased filter for nitrate removal in septic systems. Transactions of the American Society of Agricultural Engineers, 48, 1–8.CrossRefGoogle Scholar
  42. Sadeq, M., Moe, C. L., Attarassi, B., Cherkaoui, I., Elaouad, R., & Idrissi, L. (2008). Drinking water nitrate and prevalence of methemoglobinemia among infants and children aged 1–7 years in Moroccan areas. International Journal of Hygiene and Environmental Health, 211, 546–554.CrossRefGoogle Scholar
  43. Schipper, L. A., & Vojvodic-Vukovic, M. (2001). Five years of nitrate removal, denitrification and carbon dynamics in a denitrification wall. Water Research, 35(14), 3473–3477.CrossRefGoogle Scholar
  44. Davis, U. C. (2015). Nitrate (NO3) analysis by bacteria denitrification. Stable Isotope Facility, University of California at Davis. Accessed May 2016 from web link: Scholar
  45. United States EPA. (2002). Onsite wastewater treatment systems manual. EPA/625/R-00/008. Office of Water, Office of Research and Development.Google Scholar
  46. United States EPA. (2009). National primary drinking water regulations. EPA-816-F-09-004. Washington, DC: USEPA.Google Scholar
  47. Valiela, I., & Costa, J. E. (1988). Eutrophication of buttermilk bay, a Cape Cod coastal embayment: concentrations of nutrients and watershed nutrient budgets. Environmental Management, 12(4), 539–553.CrossRefGoogle Scholar
  48. Wilhelm, S. R., Schiff, S. L., & Cherry, J. A. (1994). Biogeochemical evolution of domestic waste water in septic systems: 1. Conceptual model. GROUND WATER, 32(6), 905–916.CrossRefGoogle Scholar

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Charles P Humphrey
    • 1
  • Jordan Jernigan
    • 1
  • Guy Iverson
    • 2
  • Brent Serozi
    • 1
  • Michael O’Driscoll
    • 3
  • Sushama Pradhan
    • 4
  • Eban Bean
    • 5
  1. 1.Department of Health Education and PromotionEast Carolina UniversityGreenvilleUSA
  2. 2.East Carolina UniversityGreenvilleUSA
  3. 3.Department of Geological SciencesEast Carolina UniversityGreenvilleUSA
  4. 4.North Carolina Department of Health and Human ServicesRaleighUSA
  5. 5.Department of Engineering, Institute for Coastal Science and PolicyEast Carolina UniversityGreenvilleUSA

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